1. Field of the Invention
This invention relates to and has among its objects the provision of novel apparatus and methods for collecting and transferring particulate material. It is a particular object of the invention to rapidly and completely collect and transfer fractions of adsorbent chromatography material. Further objects of the invention will be evident from the following description wherein parts and percentages are by weight unless otherwise indicated.
2. Description of the Prior Art
Absorbent chromatography, for example, thin-layer chromatography has proven to be a useful technique for qualitatively and quantitatively separating small amounts of components of a mixture. Generally, a chromatographic adsorbent such as silica gel, alumina, cellulose, or the like, is adheringly applied to a support, e.g., a glass plate. The mixture to be separated is applied to one end of the adsorbentladen support, which end is then placed in a developing fluid generally an organic solvent or mixture of organic solvents appropriately selected to achieve sufficient separation of the components of the mixture. The developing fluid travels in an upwardly direction bringing along the components of the mixture. The rate of travel of the mixture of components is dependent upon their relative attractiveness to the adsorbent and the result is a separation of the components of the mixture. The location of the components on the adsorbent support can be determined by techniques well-known in the art. Once the separated components are located, the zones or fractions of chromatographic material containing a specific component are loosened from the support and transferred to a collection vessel. The problem is that cross contamination of the separated components occurs during the transferal and this cross-contamination reduces the effectiveness of the chromatographic separation.
Zone collectors for thin-layer chromatographic fractions are known in the art. Typical examples are described in:
Janak, J. (1962) Nature (London) 195, 696-697; PA1 Ritter, F. J., and Meyer, G. M. (1962) Nature (London) 193, 941-942; PA1 Goldrick, B., and Hirsch, J. (1963)J. Lipid Res. 4, 482-483; PA1 Spikner, J. E., and Towne, J. C. (1963) Chemist-Analyst 52, 50; PA1 Nagel, J. N., and Dittmer, J. C. (1969) J. Chromatog. 42, 121-123; PA1 Levitt, M. J. (1971) Chromatographia 4, 75-76; PA1 Sudilovsky, O., and Hinderaker, P. H. (1972) Anal. Biochem. 45, 525-529; and PA1 Preiss, B. (1977) Anal. Chem. 49, 671-672.
The known collectors have one or more of the following disadvantages. First, a subsequently collected and transferred zone can be contaminated by adsorbent from a previous collection adhering to the collector. Second, porous members in the known devices often become clogged with adsorbent material. Third, the prior art apparatus require cleaning and drying after collection of one sample and before collection of another. Fourth, a separate device oftentimes is required for each fraction collected.